Pilot burner



Sept. 15, 1970 J. 'r. ALGER 3,523,754

PILOT BURNER Filed Dec. 16, 1968 2 Sheets-Sheet 1 INVENTOR. JERRY T. 'ALGER A'ITTORN E Y.

Sept. 15, 1970 J. T. ALGER 3,528,754

PILOT BURNER Filed Dec. 16, 1968 2 Shets-Sheet 2 INVENTOR.

JERRY T. ALGER ATTORNEY.

United States Patentv Office 3,528,754 Patented Sept. 15,, 1970 3,528,754 PILOT BURNER Jerry T. Alger, Los Alemitos, Califl, assignor to Honeywell Inc., Minneapolis, Minn., a corporation of Delaware Filed Dec. '16, 1968, Ser. No. 784,140 Int. Cl. F23n /00 US. Cl. 431-78 6 Claims ABSTRACT OF THE DISCLOSURE A target-type of pilot burner having a burner head with side channels to provide retaining flames, which perform the dual function of main flame retention and assisting in flame grounding, for a flame sensing electrode mounted on the burner so as to be heated by a flame from the burner. When a flame is present, electric current can flow through the flame or its products of combustion between the electrode and the burner head, to perform a control function in well-known control systems.

BRIEF SUMMARY OF THE INVENTION A target-type of pilot burner for use with a flame sensing electrode associated therewith wherein means is provided to produce a flame retaining flame and to provide supplemental flame electrical grounding.

DESCRIPTION OF THE DRAWINGS FIG. 1 of the drawing is a side elevational view of the invention with portions thereof broken away;

FIG. 2 is a fragmentary plan view of the burner head of the invention showing gas flow paths thereon;

FIG. 3 is a fragmentary side elevational view of the burner head showing a flame pattern at a low gas pressure;

FIG. 4 is an end view of the burner head and the flame electrode showing the flame pattern illustrated in FIG. 1; and

FIG. 5 is a similar end view of the burner head and electrode showing a flame pattern as also illustrated in FIG. 3.

DETAILED DESCRIPTION OF THE INVENTION The reference numeral 11 designates a tubular burner body adapted to be connected to a gas supply line and having a reduced diameter portion 11a which provides an abutment shoulder 11b against which a flange 12a of orifice member 12 may abut. A target-type of burner head 13 has a cylindrical portion 13a that fits snugly in the reduced diameter portion 11a of the burner body. The head also has an inwardly struck portion 13b that necks down the distribution chamber 14 and provides an outlet port 14a that is curved on its lower side and substantially flat on its upper side. An extension 15 of the head 13 provides a spoon-shaped target portion 15a which is adapted to deflect gas and/or a flame issuing from the outlet 14a in an upward direction. Extending upwardly and outwardly from the end of the target portion 15, in a diverging relationship to each other, are two channel-shaped extensions or wings 16 and 17 that receive portions of the gas and/or flame at each end of the opening 14a, to provide retaining flames for a central flame. The central flame results from the burning of the gas issuing from the center of the opening 14a onto the target area 15a and extends upwardly between and swipes over inner walls of the two channelshaped members.

The inner walls 16a and 17a of the wings are considerably larger in area than the outer walls 16b and 17b. The increased area of the inner walls over the outer walls are substantially triangular in shape in the preferred embodiment of these wall constructions. It is thus seen that gas passing through the burner body 11 and orifice 12b of the orifice member 12, will jet outwardly throughout the length of the orifice 14a and divide into three separate flames. The central flame is the main and larger flame and will be directed by the target portion 15a and form an upwardly and forwardly extending flame that will be substantially uniformally distributed around a flame sensing electrode 18 located above the target member, at various manually adjusted high gas pressures. At adjusted lower gas pressures the main flame, as illustrated in FIGS. 3 and 5 of the drawing, will be below the electrode but the head and products of combustion therefrom will rise and envelop the electrode. The flames on the two sides of the main flame are guided by the channel-shaped wings so as to cause the side flames to be shielded from drafts and to end up joining the main flame as the flames are guided in a curved path through the channel-shaped wings. This provides draft protected flames that will reignite the main flame in the event that the main flame is blown out by unusually large drafts. Also, these side flames, by flowing over the surfaces of the channel-shaped wings, provide additional grounding of the combined flames to provide a good electrical conducting path between the burner head and the flame electrode. The electrode is mounted in a ceramic insulating block 19 which, in turn, is mounted on the burner body 11 by means of a bracket 20. The bracket is spot welded or otherwise secured to the burner body and has tabs 20a which are bent over the insulator to hold it and the electrode in proper assembled relationship with the burner. The reference numeral 21 designates an insulated lead wire from the electrode 18 for connection to an electrical circuit, which is controlled by the presence or absence of a flame between the burner head and the electrode. Such a circuit is well known in the art and need not be further described herein.

With the invention installed in a heating system and electrically connected to the control circuit thereof, current will flow through the burner body and electrode 18 only if there is a flame present between the burner head and the electrode 18 of sufficient size to ignite a main burner adjacent the flame 11. The large area provided by the inner walls 16:: and 1711 are such that even if the flame from the burner head does not reach the electrode 18, the products of combustion from the flame provides a sufficiently good path between the surfaces of the burner head and the electrode to provide a signal to the circuit that a flame is present of suificient size to ignite a main burner. Should the flame extinguish or become so small that it would be incapable of igniting the main burner, the electrical circuit through the flame or products of combustion will be broken and result in the safe close-down of the heating installation.

As it is obvious that minor variations may be made in the invention as disclosed herein, without departing from the spirit of the invention, the scope of the invention should be determined by the following claims.

The embodiments of the invention in which an exclusive property or right is claimed are defined as follows:

I claim:

1. A pilot burner, for igniting a main gas burner and for operation of a flame sensing means, comprising a tubular burner body with a lower part thereof extending beyond the upper part thereof and forming a target-type of burner head, said head including an outwardly and upwardly extending portion with respect to the upper part and the axis of said burner body, said portion having an upwardly extending and upwardly open channel-shaped wing substantially parallel to the axis of the burner head at one side thereof for receiving a portion of the flame from said head portion to serve as a flame retainer for the remainder of the flame and to aid in the grounding of said nearest the axis of said burner having a larger area than the other wall but not of such a size as to prevent the flame in said wing from rejoining the flame on the other side of said larger area wall in the normal operation thereof.

2. A pilot burner as defined in claim 1 wherein said head has a second channel-shaped wing similar to the first mentioned channel-shaped Wing at the other side of said head portion.

3. A pilot burner as defined in claim 2 wherein the upper part of the burner body has a downwardly and outwardly inclined portion that forms with the lower part a transversely and generally horizontally extending elongated outlet directed toward said head portion.

4. A pilot burner as defined in claim 2 wherein the larger area channel walls are generally triangular in shape.

5. A pilot burner as defined in claim 4 wherein one edge "of.the.generallytriangularly shaped .Wall areas is at.the.top

References Cited UNITED STATES PATENTS 12/1960 Alger 431349 9/1964 Loveland 431-350 X CARROLL B. DORITY, JR., Primary Examiner US. Cl. X.R. 431349, 350 

